Field of the Invention
The present invention relates to a lampholder, and more particularly to the E26 plastic lampholder that can be manufactured, assembled and electrically connected more conveniently.
Description of the Related Art
Bright light is a driving force for improvements in all aspects of human activities. Without the invention of bright lights (such as light bulbs) and a series of subsequent improvements and modifications, human beings cannot have such rapid advancement in all aspects. The introduction of tungsten light bulbs was a great invention of mankind, In the principle of the tungsten light bulbs, the resistance of an electrical conduction is used to heat a tungsten filament to incandescence, so as to emit light, since an amount of over 90% of the electric energy consumed by the tungsten light bulb is converted into heat energy, and only an amount of 10% of the electric energy is used for emitting light. Obviously, the tungsten light bulbs have the drawbacks of high power consumption and low luminous efficiency. In recent years, government and private sectors of different countries in the world spare no effort to implement power saving and carbon reduction to maximize the utility of global resources and protect the ecology and environment instead of overdeveloping them. Particularly, in the aspect of illumination, various different power-saving fluorescent light bulbs and LED light bulbs are developed to replace the traditional tungsten light bulbs having the drawbacks of high power consumption and low luminous efficiency.
In a home environment, there is a “downlight” generally installed and used at home, and the downlight is a lamp embedded into a sealed ceiling. The conventional tungsten light bulb is generally installed in the downlight and used for the purpose of illumination. Since the environment using the downlight is sealed and the tungsten light bulb generates much heat, therefore the chance of burning the construction material such as the ceiling material becomes greater, and thus the downlight becomes a potential danger to the home environment. Therefore, the downlight is gradually replaced by a cold light illumination series. In other words, the power saving fluorescent light bulb and the LED light bulb are used as a light source to substitute the downlight.
The structure of a downlight is generally composed of a lamp body and a lampholder, wherein the lamp body is a shell object having an accommodating space formed therein. During assembling, the lamp body is embedded into an embedding hole formed on the ceiling to achieve the embedding and positioning effects. The bottom of the lamp body (that faces users) may be sealed by a cover or opened without having a cover, and the top of the lamp body is opened and slightly tapered to form an accommodating slot. The lampholder can be installed, fixed, and positioned into the accommodating slot, and the lampholder is provided for connecting a power line at the top and connecting a light bulb at the bottom. Therefore, the downlight can emit light downwardly from the light bulb, and then scatter downwardly in a range surrounding the lamp body to provide illumination, since the lampholder of the downlight generally has a specification of E26, therefore such lampholder is called an E26 lampholder.
With reference for FIGS. 1 and 2 for a conventional lampholder 10 installed in a downlight, the conventional lampholder 10 is basically comprised of a housing 11, a metal bracket 12 and a metal threaded ring 13, wherein the housing 11 is made of a high temperature resistant ceramic material and formed into a cylindrical shape, and the top of the housing 11 is divided into positive and negative conductive lines 111 by a screwing or riveting means and the bottom of the housing 11 is opened inwardly; the metal bracket 12 is made of a flexible metal steel and divided into a roof portion 121 and two elastic board parts 122 disposed on both sides of the metal bracket 12 respectively, and the roof portion 121 is fixed to the top of the housing 11 (by the screwing or riveting means) for the assembling, so that the two elastic board parts 122 are extended slantingly outwardly from both sides of the housing 11 (as shown FIG. 1); the metal threaded ring 13 is installed from the bottom of the housing 11 and coupled to the conductive line 111 of one of the electrode (negative electrode) of the metal threaded ring 13, so that the conductive line 111, the housing 11 and the metal threaded ring 13 are fixed to one another through the aforementioned screwing or riveting means, and the conductive line 111 of the other electrode (positive electrode) is coupled to a cathode conductive plate 112 by the screwing or riveting means (as shown in FIG. 1), and the cathode conductive plate 112 is independently situated within an open range at the top of the metal threaded ring 13.
After the downlight is assembled, the lampholder 10 is installed and positioned in the accommodating slot at the top of the lamp body of a downlight, so that the elastic board parts 122 disposed on both sides of the metal bracket 12 is latched to the wall of the accommodating slot at the top of the lamp body, so as to achieve the effect of securely fixing the lampholder 10 to the accommodating slot at the top the lamp body. When the whole downlight is installed to the ceiling, the lamp body of the downlight is embedded into the embedding hole formed on the ceiling, and the downlight is secured installed to the embedding hole by a latching means; then the conductive lines 111 are electrically connected and conducted with two electrodes of a power line connected to the mains power, so that a switch on the wall which is connected to the power lines may be used to control and turn on/off the power supply; and finally the light bulb is installed by extending the light bulb from the bottom of the lamp body, and a threaded joint screw of the light bulb is installed and secured into the metal threaded ring 13 of the lampholder 10. Now, the top of the threaded joint screw of the light bulb abuts against the cathode conductive plate 112 to electrically conduct the conductive line 111 of the positive electrode, and the threaded portion of the threaded joint screw of the light bulb is electrically conducted with the conductive line 111 of the negative electrode through the metal threaded ring 13.
The conventional lampholder 10 is a product that has been in existence for a longtime, and its housing 11 is made of a high temperature resistant ceramic material to resist the large amount of heat generated by the tungsten light bulb. However, the power saving fluorescent light bulb and LED light bulb (cold light illumination series) are used as a light source of the downlight instead. In summation, the conventional lampholder 10 has the following drawbacks and requires improvements.
1. The conventional lampholder 10 must have the positive and negative conductive lines 111 connected to the top of the housing 11 by a screwing or riveting means, and the conductive lines 111 are electrically conducted with the electrodes of the power line of the mains power respectively, and such structure and connection method are complicated.
2. In the design of the conventional lampholder 10, the roof portion 121 of the metal bracket 12 and the top of the housing 11 are fixed by a screwing or riveting means, and such structure and connection method are also complicated.
3. In the design of the conventional lampholder 10, the metal threaded ring 13 and the housing 11 are connected, and then the metal threaded ring 13 carries the threaded joint screw of the light bulb, and such structure and connection method are also complicated.